You may be able to connect the audio clip connections on the PA1 to the 600ohm TEL/Tip and Ring connection on your amp, but it is not supported by Snom. Here is a detailed explanation from one of our customers, from a forum posting, that you can reference for guidance.
The PA1 speaker outputs are driven by a 4 amp class D power amplifier, the output is 8 ohms. The speaker outputs should only be hooked up to a small 8ohm loud speaker. Additionally, you can't hook up too many speakers or have very long wire runs because the amp is only 4 watts.
The line-out on the PA1 will not work for similar reasons. The line-out is misleading because it is not really a line level output like the type you would hook up to the line-in of an amplifier. The Snom documentation clearly states the line-out and line-in on the PA1 are only to be used for configuration and setup.
The Bogen amplifier is a telephone paging amplifier. It has a TEL/BAL input labeled Tip/Ring. This is a 600ohm input designed to be hooked up to the paging output of a telephone system. The Bogen also has a Music input which is a line level input designed to be hooked up to the line-out of an audio source.
The outputs on the PA1 are not compatible with the inputs of the Bogen. You can hook up the speaker outputs of the PA1 to the TEL/BAL input of the Bogen. I have seen it work, but the fact is it is not intended to be hooked up this way and can cause problems.
The solution is to use a device that will convert the 8ohm speaker output of the PA1 to the 600ohm TEL/BAL input of the Bogen. The Radio Design Labs RDL - STP-1 Universal Audio Attenuator is designed exactly for this purpose. Here is a link to the product page and datasheet.
This is the device that will allow you to correctly hook up the Snom PA1 to almost any paging system or paging amplifier. The datasheet has hookup diagrams for connecting different inputs to different outputs. You can convert the 8ohn speaker output of the PA1 to a 600ohm input for use with most telephone paging amplifiers. You can convert the 8 ohm speaker output to a line level and hook it up to any amplifier with line level inputs. It is quite a versatile little device for the $50.00 or $60.00 USD price tag.
Note: Some customers have reported success using the RDL TX-8a when connecting the PA1 to a line level input on an external amplifier.